Still images are played from 1 to any number of times, over and over; they have no duration. You can load still images on video tracks just like you do for any video file. When loaded on the track, use the down arrow on the timeline so you can see the single frame. To extend the length of the image, drag its boundaries just as you would do with regular video media. You can drag the boundaries of a still image as much as you want. Images in CINELERRA-GG have the ability to be dragged to an infinite length. Alternatively, you can define the initial length of the loaded images. The parameter is set in the Images section of the Settings → Preferences → Recording window.
Unless your original material comes from a digital source using its best resolution (like a digital camera), the first thing you might have to do before you can use it is to somehow capture the assets into a usable digital medium. For old photos, paper maps, drawings or diagrams, you can scan them into a file format like PNG, TIF, TGA or JPG files by using a digital scanner.
Rendering a video to a single image causes the final image file to be overwritten for every timeline position. The rendered file is a single still image of the last frame of the video.
The CINELERRA-GG Community, 2021